Knitting method and machine



Dec. s, 1936. P, w Blsmw 2,063,026

KNITTING METHOD AND MACHINE F16. l i 48 P. w. BRlsTow 1 2,063,026 'KNITTING METHOD AND MACHINE Filed May 8, 1935 4 Sheets-Sheet 2 l 2 f g3 90 34 l. v /04 m l 4 43 F/G. 7. /73 F7616.

KNITTING METHD AND MACHINE Filed May 8, 1935 4 Sheets-Sheet 5 Dec. 8, 1936-.. p w BRlSTOW 2,063,026

KNITTING METHOD AND MACHINE Filed May a, 19:55 4` sheets-sheet 4 Patented Dec. 8, 1936 UNITED STATES PATENT OFFICE KNITTING METHOD AND MACHINE Paul W. Bristow, Laconia, N. H., assignor to Standard-Trump Bros.

Machine Company,

Laconia, N. H., a `corporation oi.' Delaware Application May ,8, 1935, Serial No. 20,312

11 Claims.

manipulations of specially designed sinkers or ele' ments associated rtherewith as the stitches are being drawn.

The character of action of the sinkers or other elements upon the yarns may vary depending upon the character of the associatedA elements, the feed of the yarns, etc., but in all cases of such reverse plating there is involved some variation in movement of the sinkers, or associated elements, the variations being attained through suitable controlling mechanism.

In an application led by Harold E. Houseman on January 25, 1935, Serial No. 3,376, there is disclosed an' improved controlling mechanism whereby elaborate patterning may,be secured.

through selective plating and reverse plating, a1- though the mechanism involved is of a quite simple character. In said application the controlling .elements are shown asapplied to a sinker reverse plating mechanism in which specially formed sinkers are provided and'means associated therewith are used to project the sinkers inwardly prematurely at predetermined times to cause the loops to be drawn either in front of or behind the nibs of the sinkers to thereby effect either normal or reverse plating. In most mechanisms heretofore used for producing sinker reverse plating, the sinkers or elements associated individually therewith are provided with a number of butts. -Unless such number of butts is objectionably increased, however, to an extent taking up an undue amount of space and giving,

rise to objectionable lateral thrusts, there is a detlnite limit to the character of patterns which may be produced. kIn accordance with said application, there is provided a selecting methodand means for securing the varying operations of sinkers or elements associated therewith at desired times, which method and means are'adapted for the production of very elaborate patterns involving numerous variations in selection.

In those controlling arrangements which uti lizebutts on sinkers or other elements associated with-sinkers, the patterns produced were generally and almost necessarilyy of a quite simple character, because of the limited variations permitted by the controlling mechanism. Since a normal or reverse plating condition of the yarns in such simple patterns extended over a considerable number of successive wales, no difculty was generally experienced in securing the changes from normal to reverse plating, and vice versa; at denite needles. The controlling arrangement of the H. E. Houseman application just referred to, however, permits a wide range of selectivity-and consequently very elaborate patterns involving, for example, quite. narrow vertical stripes, blocks made of reverse plated spots instead of being solid, etc., to produce which patterns it is necessary that the yarns be continuously twisted back yand forth so that reverse plating may occur over but one or very few successive wales, followed by a similar quite short extent of normal plating, to be again followed by reverse plating. It is one object of the present invention' to insure that such continuous reversal of the yarn positions may be effected without the condition of the yarns in a sinker wale affecting the yarns in an adjacent needle or vice versa; in other words, so as to avoid streak-oils.

It is known to impart to the sinkers or other elements which are controlling reversal of the yarns -a slight outward movement just as the yarns are being drawn over the sinkers to aid to some extent in the reversal of the yarns but primarily to secure equalization of the reverse and normal plated loops to prevent puckering of the -v fabric. In accordance with the present invention, provisionl is made for securing such outward movements of the sinkers or other elements at precisely the right times so as to effect the production of very clean reverse plating. Extreme precision is very necessary; in fact, it has been found that the slightest adjustment of the other madefor nely adjusting the cam which controls lthese outward sinker movements to compensate for any conditions which might arise and secure the proper sinker movements to produce clean reverse plating. l

Another object of the present invention relates to the proper control of the fabric loops when reverse plating is takin: place. After plated loops have been drawn over the backs of the sinker nibs, they arecaused to slip over to the front of them when the needles ride up the 4end cam. Frequently, especially if the fabric is loose, when they slip forward they will pull the loops of the previous course, which are in the sinker throats, out of the throats so that the fabric gets above the' sinkers and therefore out of control. This action is avoided in accordance with the present invention by a second depression of the needles after they have moved up the end cam to a point just below the sinker nibs whereby the loops are carried 'downward and at the same time a supplementary sinker cam backs the sinkers away as the needles descend and then permits them to move in as the needles reach their low point to cause the throats of the sinkers to reengage any loops which were previously lost.

- Fig. 2 is a diagrammatic perspective view indieating the production of normal and reverse plating and particularly movements of sinkers during such action;

Fig. 3 is an inside development of various needle, jack, sinker and other associated cams:

Fig. 4 is a diagrammatic plan view, partly in section, showing certain cams and cam controlling means;

Fig. 5 is a horizontal section showing controlling devices for eiecti'ng selection; o

Fig. 6 is afragmentary elevation showing the same subject matter as Fig. 5; l f

Figs. '7y and 8 are detail views of sinker controlling cam members; and

Fig. 9 is an enlarged diagrammatic perspective view showing certain specific events in reverse plating.

The knitting machine which is speciilcally illustrated for the purpose of showing the inven tion is, in general, of conventional character and only sov much of the machine is illustrated as is necessary for a clear understanding of theV invention. 'Ihe machine comprises an elongated rotary needle cylinder 2 rotated through the medium of a ring gear 4, which cylinder is provided with the usual slots 6 for the reception of needles, and .other associated parts.' The needles are of the usual latch type and are provided withbutts I8 and shoulders I2 located, as illustrated, above the butts. The cylinder' is vertically adjustable for the accommodation of different yarns. or for stitch variation by mechanism of the type shown in H. E. Houseman Patent No. 1,927,568, f which mechanism' comprises vertically movable pins 5 'on which ring gear 4 rests.

Located in the needle slots above the shoulders I2 are jack guides I4 held normally in an upper position by spring bands I1 above andbelow small projections indicated at I6. The projections |6 are so formed as to-tend to latch' the jack guides ih upper position, but when sumcient force is applied, tend to cam the lower of the spring bands outwardly to permit the jack guidesto move down. Each .of the jack guides is provided with a butt I8 designed tovbe acted upon by suitable cams as described hereafter. il; e

order to provide for the proper guidance of jacks 20, each of the jack guides is provided with upper and lower arms, respectively designated at I8 and I5, designed to embrace the inner end of a jack 20 which is guided within a slot in sinker dial 28 aligned with a corresponding needle slot. Each ofthe jacks 28 is provided with an upwardly extending arm 23 having a laterally turned upper end designed to engage a downward projection 36 formed on an adjacent sinker.. The corresponding sinkers are, of course, slightly displaced circumferentially from their operating jacks inas much as they must pass between the needles,

and the turned ends of the arms 23 insure proper cooperation between' the jacks `and sinkers. Each of the jacks is, furthermore, provided with an upwardly extending butt 22l and one or more butts 83, only one oi' which is shown in this case.

-A plurality of butts may be provided ii' more elaborate control is desired, as disclosed in the Harold E. Houseman application referred to above. 'I'he butts 22 are arranged to be acted upon by cams at proper times to effect inward and outward movements of the Jacks while the butt 83 is arranged to be acted upon to effect inward movements thereof.

The sinker dial 28 is surmounted by the usual sinker cap 24 which carries sinker operating cams, described below, and is arranged for limited circumferential `movement in the usual fashion. .Besides the cams designed to operate onthe butts 31 oi' the sinkers, this sinker cap also carries cams 25, 53 and 4| arranged tooperate at suitable times upon the butts 22 of the jacks 28.

The sinker dial 28, which is slotted on its top for the sinkers and onrtits bottom for the jacks, rests on the cylinder walls. Four segmental clamp rings 28 pull the dial down against the cylinder walls and alsoform a fulcrum for the rocking of the jacks. 'I'he rings 26 are drawn stitches are drawn to effect reverse plating. The sinkers are provided with the vusual butts 31v acted upon vby cams designed to impartto them their usual movements. The premature movements to efiectI reverse plating Vin the present instance are imparted by cams acting upon the butts 83 of jacks 28. Cams 43, 45 and 41 are provided to act upon the sinkers. Cams 43 and 41 eiect the proper sinker movements during rotary knitting and reciprocation in a forward direction, while cams 43 and 45 eil'ect corresponding movements during knitting in a, reverse direction. A cam 4I is provided secured to the sinker cap to act upon the jack butts 22 and hold the jacks 20 inwardly at proper times to insure against their being thrown outward by centrifugal torce.

'I'he cam designatedgenerally as 43 is shown in detail in Figs. '7 and 8. This cani comprises two separate elements as shown in the figures. One of these, shown in Fig. 8, provides a cam surface |11 designed to engage the sinker butts to move the sinkers outwardly and thereafter permit the sinkers tomove inwardly as they pass the surface H8. v The other element |10 forms a continuation Abehind which there is a sloping edge 33 on which of this cam and provides an outward cam surface |1| designed to give -to the sinkers which are effecting reverse plating a slight outward reverse movement to secure proper control of the yarns as indicated below. The two cam portions are secured together by a clamp screw |14, a pin |12 carried by the cam section |10 being guided in a slot in the extension 49 of the cam member |11. By reason of the pin and slot connection between the parts, a fine circumferential adjustment of the cam |1| relative to the fixed cam |11 is provided.

Inasmuch as the usual cam 43 is cut away at its trailing end as indicated at |10 in order to permit premature inward sinker movements, the spring band 39 would normally tend to move the sinkers inwardly even though they were not acted upon by the jacks 20 and were not intended to move inwardly until acted upon by cam 41. In order to avoid such premature inward movement under spring band action, there are preferably inserted in the sinker slots special band holding bits, one for each sinker, which are adapted to be acted on by a cam indicated at 49 to hold the spring bands outwardly until such time as the sinkers which are to produce normal plating are moved inwardly by cam 41. 4Such band holding bits are well known and are not described herein, since they form' no essential part of the present controlling means. They are shown, for example, in the patent to Pons No. 1,821,848, dated September 1, 1931. Cam 49, which controls them, is formed as an upper portion of the cam 43 and is not engaged by the sinker butts but acts upon the butts of the band holding bits which are longer than the butts of the sinkers 30.

-Located in the needle slots below the needles are intermediate needle jacks 38 provided with butts 40, While below these intermediate jacks are located lower tilting jacks 42 Whose inner edges are so formed as to provide pivots 44 about which.

as horizontal axes the jacks may rock. At their lower ends the jacks 42 are provided with shoulders 46 adapted to engage cams, as will be hereafter more fully pointed out. The jacks are also provided below their pivots with butts148 which may be selectively arranged for the purpose of producing patterns. for example, containing a full complement of butts which may be selectively broken out in order to provide the necessary setup for a desired pattern.

Referring to Fig. 3, there is disclosed therein the layout of cam's arranged to act upon the needles,

jacks 20, sinkers 30 and the butts of jack guides` I4, and the intermediate and lower jacks 38 and 42. The needle stitch cams are of the usual variety and comprise the upper center cam 50 and the usual stitch drawing cams 52 and 54,the former of which serves to draw the needles downwardly during rotary knitting.

Cooperating with the lower jacks there are an upper cam 56 designed to rock the lower ends of the jacks outwardly and a series of lower cams 60 and 62 designed to rock the lower ends of the jacks inwardly. All of these cams are formed as levers and will be referred to hereafter. The lowermost of the cams designed to rock the jacks inwardly is designated differently from the others,

since it performs a somewhat different function In advance of the cams 60 there is located a fixed cam 58 which is designed to engage the shoulders 46 on the lower jacks and cause them to rise t0,

The jacks may be supp1ied,-

proper vertical alignment between the butts on the jacks and the various corresponding cams 60. There is also provided, in a position following the cams 60, a cam 66 having an upward slope 64 on which the shoulder 46 of such of the jacks 42 as have their lower ends extending outwardly may ride, whereby such jacks will be raised. A slope 68 provided on the cam 66 serves to rock the lower` ends of the jacks inwardly andthus disengage them from the top level of the c am 66. A guard cam 10 is provided to prevent possibility of damage to the jacks during reciprocation and limit their downward movements.

A cam 12 is provided designed to engage the butts I8 of raised jack guides I4 so as to depress all of the jack guides at its position. This is to preparethe jack guides for a subsequent selection.

Cams 14 and 16 are respectively designed to raise and lower needles by engagement with their butts I0 for purposes which will hereafter become apparent. The lowering action of cam 16 is continued by the usual guard cam 18. A ring of 4cams indicated at 8l serves to maintain the intermediate jacks within the needle slots. A cam face on the lower portion of this series is adapted to engage the butts 40 of the intermediate jacks to lower them and with them the lower jacks 42.

A cam 82 is adjustably mounted by a. screw and slot connection, indicated at 83', uponI a lever 84 and is arranged to act upon the butts 83 of the horizontal sliding jacks 20. A cam 86 is provided to raise the needles to a desired level.' It may be noted that the loops on needles which may be raised due to selection clear the latches as jacks pass up cam 84, While the loops on needles which are not raised clear the latches thereof at cam 54.

Besides the cam mentioned above, there are provided a cam 5| arranged to raise jack guides I4 and a cam 53 carried by the sinker cap and arranged to engage butts 22 and move jacks outwardly. Both of-these cams are used to avoid improper actions of the elements during reciprocation, and their functions will be brought out hereafter. Other cams are provided for the purpose of producing, for example, gusset toes, but need not be described since they have no direct relationship to the present invention.

A cam 81 is provided in the position indicated in Fig. 3 to move the needles downwardly after they have been raised by the cam 86. This cam 81 is\carried by a bell crank |80. There isalso provided a cam |90 for engaging the sinker butts and moving the sinkers outwardly as needles w move down under the action of cam 81.

The layout of cams having been described, reference will now be made to their controlling means. The lever 84 which carries the cam 82 is provided with an arm 90 in which is mounted an adjustable follower screw 93 arranged to be engaged by a cam 94 pivoted at 98, which cam is designed to move it against the action of spring 92 so as to cause the cam 82 to move inwardly to engage the butts 8310i the jacks 20. Movements of the cam 94 are controlled by a link connection |04 to one of a series of nested shafts indicated at |05 in Fig. 6. These shafts are provided .at their lower ends with follower arms engaging sultablecams on the main pattern drum I. The control in this respect is similar to that described in the H. E. Houseman application referred to. A spring |02 normally urges the cam A94 in a counter-clockwise direction to free the follower 93 and permit the cam 82 to withdraw outwardly.

'I'he bell crank |80 which carries the cam 81 is connected by a link |82 to the cam 94, which connection is made in such fashion that the cam 81 is withdrawn outwardly when the cam 82 is permitted to move outwardly.

A cam arranged to engage the sinker butts is pivoted at 9| to the sinker cap and lis provided with a pin connection |92 to a lever |94 pivoted at to the sinker cap and connected by a link |96 to the cam94. The link |96 is in the form of a wire extending through an eye 200 carried by the cam 94 and is provided with a head |99 arranged to be engaged by the eye. From these connections it will be obvious that the cam |90 is rocked outwardly so as to produce a retraction of the sinkers whenever the cam 82 moves inwardly. When the cam 82 is permitted to move outwardly, the sinkers under the action of the spring band 39 will restore the cam |90 to its inner position.

lThe needle circle is approximately indicated at I|4 in Fig. 4. The cams 14 and 'I6 are moved radially together and cam 'I2-is also subject to controlled radial movements through the medium of levers |36'and |38 controlled by cams |40 on the main cam drum III. 'I'he controlling ar rangements are described in detail in the H. E. Houseman application mentioned above.

Control of the cams 60, which are formed as levers pivoted at |4I, is effected by the action vupon tails thereof of tricks carried by a trick wheel |42. These tricks, which are receivable in slots in the trick wheel in the usual fashion, are provided with butts which may be selectively ari ranged to produce the desired control of the cams 60. 'Ihe trick wheel |42 is stepped about intermittently by the action .on a ratchet |44 carried thereby of a pawl |46 which is oscillated through the medium of a link |48 by the lever |50 which rides upon lugs carried by the links of a pattern chain |52 which is advanced one step upon each revolution of the needle cylinder. By a suitable setup of the lugs on the pattern chain, the trick wheel may be advanced upon each revolution of the needle cylinder or at less .frequent intervals. A guard |54 is provided for interrupting the advance of the trick wheel and for securing a setup thereof at the completion of a stocking, this beingeffected as described in the application of Stanley R. Shelmire, Ser. No. 623,- 057, led July 18, 1932.

The cam 56 is formed on a lever which has a functionally integral, adjustable extension |56 connected by a link to a lever |58 which is secured to one of a series of vertical nested shafts whose lower ends carry cams acted upon by cams on the pattern drum I.

If desired, the series of cams 60 may operate in a plurality of sets. In the machine illustrated, for example, there are three such sets.

-By reason of such arrangement, there is made may be selectively rendered operative or inoperative by control of levers |60 which engage their rear ends and pullv them away from the tricks on the trick wheel |42 against the action of the springs I6I. 'Ihe levers |60 are independently controlled by links |62 connected to arms on three of the nested shafts hereafter referred to.

The lowermost cam 62, which is also pivoted at I4I, is controlled by a connection through a link I 64 to an arm carried by still another of the nested'shafts. Cam 5I is carried by a suitable lever link-connected to one of the set of nested shafts heretofore referred to as controlled by the main pattern drums. Normally this cam 5| is out of action.

The yarns A and B, which are to be selectively normal and reverse plated, are fed to the needles in conventional fashion, for example, by being fed from yarn fingers 9 located in the throat |I of the usual latch ring. The yarn B which is the normal backing yyarn is preferably under greater tension than yarn A. If yarn changes are to be made, yarns carried by the different fingers may be selectively brought into operation at predetermined times by the usual yarn changing mechanism, involving conventional clamping and cutting devices.

The operations involved in producing normal and reverse plating by the mechanism just described will be readily understood from a consideration primarily of Figs. 3 and 4, showing the cam arrangements, together with occasional reference to the other gures, particularly Figs. 2 and 9, in the matter of details of operation of the sinkers. In Fig. 3 there are indicated in dotted lines the paths of characteristic parts of the various elements associated with the needles in the needle slots and the needles themselves. For example, at a and b there are indicated the a1- ternative paths of the needle butts, at c and d there are indicated the alternative paths of the butts I8 of the jack guides I4, at e and f there are indicated the alternative paths of the shoulders 46 of the lower'jacks 42, and at g and h there are indicated alternative paths of the butts 40 of the intermediate jacks 38. It will be noted that through the greater part ofaI revolution the butts of the needles and intermediate jacks and the shoulders of the lower jacks follow constant paths. The elements associated with the needle cylinder move to the left in Fig. 3 during rotary knitting.

Initially let it be assumed that a particular set of elements associated with one needle and an adjacent sinker are in such position that the upper end of the lower jack is at .the position of cam'56. At such time the jack guide I4 of this set of elements maybe in either upper or lower position with its butt I8 following either path c or d, depending upon the selection made prior to the previous stitch drawing operation. The intermediate jack 38 will have been lowered and will in turn have lowered the lower jack 42, the lower end of which will have been projected outwardly by cam 56 if it had not previously been in such position. The sinkers on both sides of the needle referred to will be in their inner positions. A jack 20 associated with either of these sinkers will be in one of alternative outer positions depending upon whether or not itis raised or lowered. If it is raised, 'then it may be in an extreme outer position to which it would have been thrownv by centrifugal action if unrestrained by friction. If it is in lower position, the turned end of its arm 23 will have been engaged either centrifugally or due to the action of cam 53 with the annular shoulder 2I of the upper portion of the cylinder. The needle will be in a position, following this lowering by cam 81, corresponding to the portion of the line a beyond cam 81. The loop thereon will not have cleared the latch.

As the rotation proceeds, the lower jack will ride upwardly over levelling cam 58 and its butts may or may not be engaged by one of the cams 60. A jack, the lower end of which is rocked inwardly, will, in the next stitch-drawing operation, determine the formation of a normal loop. Assuming that the lower jack under consideration was not acted upon by any of cams 60, its shoulder 46 will remain out in a position to ride up the slope 64 of cam 66 along the upper path f. 'I'he butt of the intermediate jack will then follow path h and as the end of the rise is reached, the corresponding needle will be pushed upwardly so that its butt follows path b in position to later engage cam 14. Ii', on the other hand, a lower jack is pressed inwardly by the action of one or more of cams 60, its shoulder 46 will fail toengage the slope 64 of cam 66 and will follow path e. The butt of the intermediate jack will then remain at the same level and move along path g and the needle butt will move along path a underneath cam 14 so that it will not be raised by that cam.

In the meantime, the jack 20 will be pushed inwardly by the action of cam 4| and while this jack is held inwardly the butt of jack guide I4 will reach the position of cam 12. If the jack guide is held lowered, it will pass below cam 12 without being acted upon thereby. On the other hand, if it is in raised position, it will be lowered by` cam 12 with the resun that any jack passing this point will occupy the same lower position in which it will be yieldingly retained by the location of the lower of the spring bands I1 above projection I6. The preliminary inward movement imparted to the jack 20 is for the purpose of insuring that the turned end of its arm 23 is inwardly of the shoulder 2| of the needle cylinder so that, if it is associated with a jack guide which is lowered, the turned end will pass downwardly inside the shoulder. If the jack 20 was held in its lower position, it will a1- ready have been restrained from outward movement by the engagement of the turned end of its arm 23 with shoulder 2| and will be moved only slightly inwardly by cam 4|.

If the needle has been raised as indicated above, it will ride up cam 14 and the loop which it carries will pass below its latch. When it moves along the upper portion of the slope of cam 14, its shoulder will engage and move upwardly the jack guide I4, raising the butt of this guide to the level d. Just prior to such rise, the cam 25'insures that the jack` 20 is suillciently far out so that if it rises its arm 23 will not jam against the projection 36 on the bottom of the sinker. In general, centrifugal action upon the jacks insures that they occupy outer positions engaging the shoulder. 2|. Fig. 1 shows the parts in the positions attained as the needle reaches the upper end of cam 14.

Following the selective rise of its jack guide |4,

the latter over cam 54, which serves to raise the last named needles to a latch-clearing height. Simultaneously, the raised intermediate and ylower jacks are moved downwardly by cam Il, any yarns and sinkers and movements thereof rela- 15.

raised lower jack being previously forced on the cam 66 by they action of the slope 68. Downward overrun of any lower jack is prevented by the cam 10.

Upon reaching cam 45, which only acts during reciprocation, the sinker will already occupy an inner position and consequently will be withdrawn by a portion |11 of cam 43 together with its jack 20 if the latter is in upper position and has not already been thrown out centrifugally to a greater extent. The yarns between the loops carried by the needles which have heretofore been located within the sinker throats below the nibs 3| and will at this time move slightly outwardly, lie, due to the retraction of the sinkers, upon the upper portions of the ledges 32. They continue to occupy such positions as yarns are taken for the formation of new loops.

As the position of cam 82 is reached, the needles Will have taken yarns from the feeding fingers. Cam 82 (or one of a pluralityof such cams if more than one is used) will project a jack 20 inwardly irrespective of whether it is in upper or lower position by engagement with its butt 83. If it is in upper position, fits arm 23 will engage projection 36 of its corresponding sinker and impart to the sinker a premature inward movement so that the yarns are drawn over the edge 33 of the sinker behind its nib 3|, thus eiecting reverse plating. On the other hand, if the jack 20 were in lower position, inward movement imparted to it by cam 82 would not be transferred to the sinker and consequently the yarns would be drawn over the edge 32 of the sinker in front of nib 3| to produce normal plating. Fig. 2 illustrates this action. The sinkers'indicated at n, o, p and q have passed the location of the cam 82 and have not been moved inward. As a consequence, they Will determine the formation of normal plating in their wales. On the other hand, the sinkers r and s preceding the ones just mentioned have been moved inwardly through the action of cam 82 on jacks 20 and.

events occurring at this time are precisely related l to each other to insure perfect reversev plating confined to single sinker wales. In order to bring out what occurs and how these events are related,

reference may be made to Fig. 9 which illustrates the formation of normal plating in the wales of sinkers 200, 204 and 208 and of reverse plating in those of sinkers 202 and 206. In previous,v

sinker reverse plating, the reversals of the yarnsl have not been confined to the sinker wales but have been uncontrollably extended into the preceding needle wales. If tne degree of extension into such wales was controlled, the resulting product would rbe satisfactory. But even slight variations, unnoticeable at the borders of large vreverse plated areas, become very noticeable where reverse plated loops are to stand out individually as in work produced as illustrated in Fig. 9. Unless the reversals are the same in each reverse plated'loop, an unsightly fabric results.

It has been found that perfect results depend upon the proper relationship of the needl,

' jected by knock over cam 41.

tive to each other as the old loops pop over the needle hooks. 'Ihese critical relationships may be best understood by considering particularly the yarn position diagrams at the right in Fig. 9. (For clarity of illustration, the needle and sinker spacings are exaggerated in this gure.) The yarns at a needle such as 2I0, the hook of which has not yet ,engaged them, lie with the untensioned facing yarn A inwardly and below the tensioned backing yarn B. Normally these yarns would retain their relative inner Vand outer positions as they were drawn over the ledge 32 of a retracted sinker such as 200. l f

The advanced sinker 202 is .illustrated as at a position of first contact of its butt with the retracting cam I1I so that it is at its most inward position. Just as it reaches this point, the yarn A will touch its edge behind the nib, while the following needle 2I2 will just about engage the yarn B but not A and will not have drawn yarn B downwardly to the level of A. The preceding needle 2 I4, however, -will have engaged both yarns and will have drawn them downwardlyv to such extent as to cause them to engage the ledge 92 of the retracted preceding sinker 204. The needle 2I4 will bein such position that the loop of the preceding course is just about to slip over its hook under the tension of the fabric, while the loop slipping over the hook of needle 2|6 is in engagement with the yarns in its hook. The cam |1| is provided with such angle that it fully retracts a sinker when the sinker moves through approximately the angular spacing between sinkers. l

The sinker 200 has been fully retracted by cam I1I to cause the yarn A to be displaced below and outwardly of yarn B and is just about to be pro- The needles 2li and 218 by their depressedposition and aided by sinkers 204 and 200 hold the yarns in their `normal relationship so that the reversal is totally confined to the sinker wale between them. The reversal is aided and maintained by the slipping over of the loops of the preceding course and as a result definite uniform reversal/is effected.

It will now be clear why adjustment of cam |1| is so essential for good results. The attainment of the precise relationships just mentioned Aobviously requires that the sinker retraction xnust be very accurately adjusted relative to the needle movements, or, more essentiallyyto the -engagements of the yarns with the sinkers.

smooth yarns are eected much more readily than reversals of rough, fuzzy yarns and the` amount of reversal is therefore dependent on the time of sinker retraction; Loop adjustment by needle cylinder adjustment changes the relationship of the needles Land sinkers and, pf course, the proper location of cam I1I. After all other factors are taken care of the cam I1| is positioned to secure best results.

Comparison of this method of reversal with the usual sinker reversal is worthy of note. In the usual reversal; the reversal is actually caused by a needle to the outside of the hook of which the yarns are carried by sinker retraction. The result is thatreversal occurs in both the sinker and needle wales. c

It will be clear that when two or more reversing sinkers are adjacent each other both will, of'

course, produce reversals and reversals will also occur in intermediate needle loops.A

of particular moment as regards precision of reverse plating but merely takes care of stitch equalization, thusfunctioning in this respect the same as the fixed cams heretofore provided, to prevent reverse plated loops being tighter than normal plated loops. The drawback varies with different gauges but requires no adjustment in a particular machine. The holding of the reversing sinkers in retracted position insures correction of ya'rn positions to form normal loops.

During the preceding operations, when certain of the sinkers are selectively moved inwardly, the band-holding bits function to hold out the spring band I9 to prevent the premature inward movement of sinkers which are not to be moved inwardly in spite of the fact that the operative edge |11 of the cam 43 is cut away as at |19. As indicated abovel a portion 49 of cam 43 continues to act on the longer butts of the band-holding bits to prevent the action of band 39 upon the sinkers, which will be centrifugally urged outwardly. y

If a sinker was not prematurely movedinwardly, it will be moved inwardly by the action of the usual cam 41, which serves to produce the inward movement to knock over the old loops.

The needle is now raised by cam 00 in order that the loops drawn behind the sinker nlbs may be raised so as to clear`the nibs. When this rise takes place, and particularly if the fabric is loose, when the reverse plated loops slip forward they may pull the loops of the previous course out of the sinker throats, with the result that the fabric may get above the sinkers and therefore out of control. To avoid this, the needles are again depressed by a cam 01 immediately following their rise over the end cam 06 and at the same time, by means of the supplementary sinker cam |90, the sinkers are backed away from the needles as they descend and are then again moved inwardly by the spring band as the needles reach their low pointto :cause the throats of the sinkers to reengage any loops which may have been previously lost. Since this action is only necessary when reverse plating is being effected and loops are being drawn behind the sinker nibs. provision is made, as described aboveI andV as `indicated in Fig. 4, to cause both the cams 01 and i90 to remain inoperative unless reverse plating is being done.

Further details of the operation, particularly asv regards the operation of themachine when no reverse plating is being accomplished, are given in the Harold E. Houseman application referred to above. cerned with such operations, they are ,not described hereln in detail. It is sufllcient to remark ythat the withdrawal of cams 01 and |90 from op- Since the present invention is not coneration during reciprocation prevents their interference with the formation of heels and toes.

By reason ofthe provision of the adjustable retracting cam I1I, perfectly clean-cut patterns may be produced even when the full capabilities l of the pattern mechanism described harem are What I claim and desire to protect by Letters Patent is: l

1. A, circular knitting machine including a needle cylinder, needles slidable in the cylinder, means for feeding a plurality of yarns to the front of their nibs, means for prematurely ad-` vancing certain sinkers to cause loops to be drawn behind their nibs, and an adjustable cam for retracting each of said last named sinkers when the needle preceding said sinker is passing below the fabric level to draw a new loop through one previously made.

2. A circular knitting machine including a needle cylinder, needles slidable in the cylinder, means for feeding a plurality of yarns to the needles, sinkers equipped with nibs movable between the needles and cooperating therewith in the formation of stitches, means for normally advancing sinkers to cause loops to be drawn in front of their .nibs, means for prematurely advancing certain sinkers to cause loops to be drawn behind their nibs, and an adjustable cam for retracting each of said last named sinkers when the needle preceding said sinker is passing below the fabric level to draw a new loop through one previously made, said cam being adjustable to compensate for a change of position of said fabric due to vertical adjustment of the needle cylinder.

3. A circular knitting machine including a needle cylinder, needles slidable in the cylinder, means for feeding a plurality of yarns tothe needles, sinkers equipped with nibs movable between the needles and cooperating therewith in the formation of stitches, means for normally advancing sinkers to cause loops to be drawn in front of their nibs, means for prematurely advancing certain sinkers to cause loops to be drawn behind their nibs, and an adjustable cam for retracting each of said last named sinkers when the yarns in the needle preceding it are being drawn through the loop on said needle and are being turned by said loop as it slips over the needle hook.

4. A circular knitting machine including a needle cylinder, needles slidable in said cylinder,

means for feeding a plurality of yarns to the needles, members movable between the needles and arranged to engage the yarns when stitches are being drawn, said members having nibs movable between the needles, means for selectively controlling movements of said members to cause loops to be drawn in front of said nibs to produce l normally plated loops and behind said nibs to produce reverse plated loops, and additional means acting immediately after loops have been formed to locate the reverse plated loops in front of said nibs. v

5. A circular knitting machine including a needle cylinder, needles slidable in said cylinder, means for feeding a plurality of yarns to the needles, sinkers movable between the needles and arranged to engage the yarns when stitches are being drawn, said sinkers having nibs movable between the needles and providing throats for the receptionv of loops, means for selectively controlling movements of said sinkers to cause loops to be drawn in front of said nibs and'into the throat to produce normal plated loops and behind said nibs to produce reverse plated loops, -and additional means acting immediatelyafter floops have been formed to locate the reverse plated loops in the sinker throats, so that they will be under control of the sinkers and will be cast oi! in the next course of knitting.

6. A circular knitting machine including needle cylinder, needles slidable in said cylinder, means for feeding a plurality of yarns to the needles, sinkers movable between the needles and arranged to engage the yarns when stitches are lbeing drawn, said sinkers having nibs movable between the needles and providing throats for the reception of loops, means for selectively controlling movements of said sinkers to cause loops to be drawn in front of said nibs and into the throat to produce normal plated loops or behind said nibs to produce reverse plated loops, and means for locating the reverse plated loops in the sinker throats comprising a cam for retracting the sinkers and a cam for lowering the needles while said sinkers are retracted to draw the loops below their nibs.

7. A circular knitting machine including a needle cylinder, needles slidable in said cylinder, means for feeding a plurality of yarns to the nee- Vdles, sinkers movable between the needles and arranged to engage the yarns when stitches are being drawn, said sinkers having nibs movable between the needles and providing throats for the reception of loops, means for selectively controlling movements of said sinkersto cause loops to be drawn/in front of said nibs and into'the throat to produce normal plated loops or behind said nibs to produce reversed plated loops, means for locating the reverse plated loops in the sinker throats comprising a cam for retracting the sinkers and acam for lowering the n eedles while said sinkers are retracted to draw the loops below their nibs, and means ,whereby said sinker retracting cam and said needle lowering cam are rendered active only when reverse plating is taking place.

8. The method of eiecting reverse plating on a knitting machine provided with independent-- ly movable needles and sinkers, the sinkers being provided with nibs having -sloping backs, comprising feeding a plurality of yarns to the needles, normally advancing certain sinkers to cause loops to be drawn in front of their nibs, prematurely advancing certain sinkers to cause loops to be drawn on the sloping backs of their nibs, and retracting each of said last named sinkers when the needle preceding said sinker is passing below the fabric level to draw a new loop through one previously made.

9. 'I'he method of effecting reverse plating on a knitting machine provided with independently movable needles and sinkers, the sinkers being provided with nibsl having sloping backs, comprising feeding a plurality of yarns to the needles, normally advancing certain sinkers to cause loops to be drawn in front of. their nibs, prematurely advancing certain sinkers to cause loops to be drawn on the sloping backs of their nibs, and retracting each of said last named sinkers when the yarns in "the needle preceding it are being drawn through the loop on said needle and are being turned by said loop as it slips over the needle hook.

10. The method of eecting reverse plating on a knitting machine provided with independently-movable needles and sinkers, the sinkers being provided with nibs having sloping backs, comprising feeding a plurality of yarns to the needles, normally advancing certain sinkers to cause loops lto be drawn in front of their nibs, prematurely advancing certain sinkers to cause loops to be drawn on the sloping backs of their nibs, and retracting each of lsaid last named .sinkers when the needle preceding said sinker is passing said reversing sinker that reverie plating will 76 be coniined to thel wale fofrmed'by said s inker when the sinkexs on either side o1 it are being projected normally to 'effect regular plating'.

11. The method of eil'ecting reverse plating on a knitting machine provided with independently movable needles and sinkers, the fsinkers being provided with nibs having sloping backs, comprisingieeding a plurality of yarns to the needles, normally advancing certain sinkers to cause loops to be' drawn in front of their nibs, prematurely advancing certain sinkers to cause loops to beY drawn on the sloping backs o! their nibs. and retracting eachotsaid last named sinkers when the yarns in the needle. preceding it are being drawn. through the loop on said'needle and are being turned by said loopas it slips over the needle hook, so timing the retraction ot said reversing sinker that vreverse plating will beconilned to the waleiormed by said sinker when the sinkers on either side of. it are being projected normally to eiiect regular plating.

lPAUL. w. BRIs'roW. 

